Database engine

Newbie & Debugging Questions
#1

I’m looking into rewriting Tectonicus’ cache handling, which currently uses about a gazillion flat files. This works but it’s pretty rough on the HDD both in terms of access and number of files/directories.

I’m interested in moving to some kind of DB backend, but last time I tried using a proper DB via Java I got bogged down in configuring JDBC sources and a whole load of enterprise-y wank that I didn’t want or need, and most actual users would run as soon as they saw they had to do it.

Basically I want a file backed database which requires zero configuration on the user’s part and preferably is written in pure java. Sql support is optional, I just need to be able to store and manipulate data sets too big to hold in memory. HyperSQL is the only thing I’ve found so far ( http://hsqldb.org/ ). Can anyone recommend any others?

#2

http://www.h2database.com/html/main.html

#3

Interesting! Are there any particular reasons why you’d recommend h2 over HyperSQL?

Someone also suggested that I might be better using EhCache instead but I’ve also not used that so I’ll have to look into it. All I really want are List and Map implementations which can page in and out of disk transparently so they can be huge without requiring gigs of RAM usage.

#4

Haven’t used them for complex things. Just as a backend for unit-tests (in-memory DB).

It works… :persecutioncomplex:

#5

+1 for H2, also used for an in-memory database, fast, easy to use.

#6

I believe H2 is a newer DB that was based on or forked from hsqldb. I’ve used H2 in unit tests for work and I’m very pleased with its performance.

#7

if you are fine with key value stuff you might want to look at infinispan. similar to ehcache it has a local mode and eviction policies.

#8

I’m fine with key/value stuff as long as I can also iterate over the whole collection in a way that doesn’t drag the whole thing into memory. Most of the documentation for EhCache is a bit vauge about that. Do you know if infinispan can do that?

#9

What’s up with HSQLDB? Why did H2 fork it? HSQLDB looks like the dog’s bollocks.

Cas :slight_smile:

#10

mmh i am not sure if a cache really fits your needs. infinispan should not load all entries when iterating over the keyset. Are those flat files java objects or resource files like sound-, image- and textfiles? If they are java objects a cache can be a good idea. Did you look into virtual file systems for java?

#11

I looked back into it and I misremembered, H2 wasn’t a fork they were just started by the same developer. HSQLDB was started first, he dropped it and then 4 years later he released H2. Other developers have since picked up HSQLDB’s code base.

Visiting here, http://www.h2database.com/html/performance.html it would appear that H2 generally outperforms HSQLDB. Although it should be taken with a grain of salt since it’s from the H2 site.

#12

I’ve used both hsqldb and h2, and they’re both excellent databases. hsqldb has greater compliance to the ISO SQL standard, if that turns your crank, and H2 has interesting features built in, like a web admin UI, and a cute feature that prevents sql injection by requiring bound parameters for all query values. They’re both ridiculously fast and they both blow the doors off sqlite when your data gets past a hundred megs or so.

#13

[quote=“sproingie,post:12,topic:37529”]
Every database manufacturer should do this. Provide backwards compatibility through -SECURITY_HAZARD commandline argument.